The present invention relates to a gate protecting device for hydraulic machines to avoid destruction of control linkage of gates.
In hydraulic machines, where a series of wicket gates are provided around an impeller runner to control and guide water flow through the runner, it is desirable to employ a gate protecting device between wicket gates and a gate control ring to avoid destruction of the gate control ring when a gate's movement is restricted by an obstruction struck between adjacent gate vanes or between a gate vane and a stationary vane arranged around the gate vanes.
Exemplary of the prior art is U.S. Pat. No. 3,060,706 to P.D. Hess wherein a shear lever transmitting force between a gate control ring and a gate lever is secured by a shear pin and when the shear pin is severed, relative movements between the shear lever and the gate lever are frictionally retarded.